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Author: Subject: Grass/Weed killer
Neil
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[*] posted on 22-6-2011 at 06:00


Like TSP? You see some people scrubbing off their roof with Tri Sodium Phosphate once every few years and inevitably the moss comes back faster then ever once it gets a hold of the remaining phosphate.
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Panache
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[*] posted on 23-6-2011 at 20:33


Quote: Originally posted by Arthur Dent  
Nitric acid? Wouldn't this promote the growth of weeds and grass by supplying ample amounts of nitrates?

I remember some 20 years ago, I discarded a small amount of ammonium nitrate and nitric acid mixture by throwing it down a sewer that was surrounded by grass. A little bit of the mix fell on the edge, effectively melting off the vegetation and killing it good.

But a year later, the same edge of the sewer hole was surrounded by thick, luxurious grass that grew nearly 10 times faster than the surrounding lawn. This phenomenon lasted for a good 3 or 4 years...

Personally, I would avoid anything containing nitric acid, as this might kill the weeds on the spot, but will probably promote growth at a later date.

Robert


i guarantee that 10% nitric dispersed at around 100mL/m2 will result in surface of the moon barrenness for all eternity, but if you want it unbarren, neutrasliing will result in the phenomena you describe, i imagine your solution to not have been overly acidic and/or ample flushing occured over time..

While we talk about weeds can i ask regarding my lawn, see it's rainy and wintery in melbourne atm, the new lawn i sowed some weeks ago (only about 15m2) initially sprouted nicely but continued growth has proceeded very sluggishly, if i was to give it some love from a couple of merc vapour uv emitters each day for a few hours would i notice a significant improvement or would i be wasting my time? Is temperature more important than anything than anything else is perhaps what i'm asking?




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Neil
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[*] posted on 24-6-2011 at 05:22


Do you have a speculated route by which the nitric maintains it's moon-death grip?


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AJKOER
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[*] posted on 24-6-2011 at 20:04


OK, if you want to do make weedkiller yourself cheaply.

Add 2/3 of a bottle of bleach (NaClO) to equal amount of vinegar. Let stand. Add remaining 1/3 bottle of bleach. Done.

For chemist, the acetic acid reacts with the NaClO to form HClO. It also neutralizes the small amount of NaOH in the bleach that hinders the disproportionation of the NaClO into NaClO2 and then NaClO3 (Sodium Chlorate is a commercially used weed killer).

Then, the HClO oxidizes the added NaClO to NaClO3 and is, itself, reduced to HCl.

2 HClO + NaClO --> NaClO3 + 2 HCl

Source: http://www.scribd.com/doc/30121142/Dichlorine-Monoxide-Hypoc...
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LanthanumK
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[*] posted on 25-6-2011 at 02:49


HCl reacts with NaClO3, you know (I hope), so your arrow is backwards to a certain extent. Here are the reactions given on Wikipedia:

HClO3 + HCl → HClO2 + HOCl
HClO3 + HClO2 → 2 ClO2 + Cl2 + 2 H2O
HOCl + HCl → Cl2 + H2O

http://chemistry.about.com/b/2007/09/26/the-killing-power-of...

It works better as a fumigator than a weedkiller. If you want to make NaClO3 without the well-known bleach-vinegar reaction, warm bleach in a corrosion-resistant container until it disproportionates, then use the salty NaClO3 solution. You may selectively crystallize it to get pure NaClO3.

All because a chemical synthesis is shown on a chemistry website does not mean that the average ignorant person will know how to make chlorine safely.




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Morgan
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[*] posted on 25-6-2011 at 10:31


No surprise.
Roundup: Birth Defects Caused By World's Top-Selling Weedkiller, Scientists Say
http://www.huffingtonpost.com/2011/06/24/roundup-scientists-...
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